Flexible Display TFT Layout for Low-Power Bending Areas
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Solution Overview
Problem
Current display devices face challenges in achieving low power consumption, which is essential for portable and wearable devices, as existing technologies have limitations in reducing power consumption while maintaining performance and portability.
Innovation Solution
The display device incorporates a first thin-film transistor with a polycrystalline semiconductor layer and a second thin-film transistor with an oxide semiconductor layer in the active area, along with openings in the bending area to minimize stress and simplify the manufacturing process by using the same material for source and drain electrodes, and forming openings in the inorganic insulation layer to expose signal links and the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a display device uses conventional transistor structures and materials, then manufacturing processes are simpler, but power consumption is high and resolution is limited
Solution Approach 1:
The display device divides the transistor structure into two distinct types: first thin-film transistors with polycrystalline semiconductor layers and second thin-film transistors with oxide semiconductor layers. This segmentation allows each transistor type to be optimized for specific functions, with oxide semiconductor transistors providing low power consumption characteristics while polycrystalline transistors handle high current driving requirements, thereby resolving the contradiction between power consumption and device complexity.
Solution Approach 2:
Different semiconductor materials are applied to different transistor locations based on functional requirements. Oxide semiconductor layers are used in transistors requiring low leakage current and low power consumption, while polycrystalline semiconductor layers are used in transistors requiring high current driving capability. This local quality differentiation enables the display device to achieve overall low power consumption without compromising performance, resolving the contradiction between power consumption and device complexity.
2Ease of manufacture
If multiple different materials are used for source and drain electrodes, then electrical performance is optimized, but manufacturing process complexity increases
Solution Approach 1:
The source and drain electrodes are designed with a multi-layer structure where each layer serves multiple functions. The first conductive layer provides both electrical conductivity and structural support, while the second conductive layer enhances electrical performance and provides stress compensation. This universal multi-layer design achieves optimized electrical performance without significantly increasing manufacturing complexity, as the same multi-layer electrode structure is used throughout the display device.
Solution Approach 2:
The source and drain electrodes are constructed as composite structures with multiple conductive layers having different material properties. This composite material approach allows optimization of electrical performance through material selection while maintaining manufacturing simplicity by applying the same composite structure universally across all electrodes in the display device.
3Adaptability or versatility
If inorganic insulation layers are present in bending areas, then structural integrity is maintained, but flexibility and portability are reduced
Solution Approach 1:
The inorganic insulation layer is selectively removed from the bending area while being retained in the non-bending active area. This extraction approach maintains structural integrity in regions where rigidity is needed while enabling flexibility in bending areas, thereby resolving the contradiction between flexibility and structural integrity. The opening in the inorganic insulation layer allows the display device to be bent without causing cracks or damage to the rigid insulation layer.
Solution Approach 2:
The inorganic insulation layer is segmented into two regions: a first inorganic insulation layer in the non-bending active area that maintains structural integrity, and a removed or thinned region in the bending area that enables flexibility. This spatial segmentation allows the display device to simultaneously achieve structural integrity where needed and flexibility where required, resolving the contradiction between these two opposing requirements.
Data Source
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AI summary
Disclosed is a display device capable of realizing low power consumption since a first thin-film transistor having a polycrystalline semiconductor layer and a second thin-film transistor having an oxide semiconductor layer are disposed in an active area. In addition, an opening formed in a bending area is formed to have the same depth as at least one of a plurality of contact holes formed in at least one inorganic insulation layer, which is disposed in the active area, and source and drain electrodes of the second thin-film transistor and source and drain electrodes of the first thin-film transistor, which are disposed below the oxide semiconductor layer, are formed in the same plane using the same material, which simplifies the manufacturing process of the display device.